1. Field of the Invention
The present invention relates to a printing apparatus and, more particularly, to a printing apparatus which develops dot pattern information of bit map fonts in accordance with text information such as character codes or the like and prints by a printer mechanism.
2. Related Background Art
Hitherto, in a printing apparatus such as a laser beam printer or the like, when text information comprising character codes or the like is supplied from a host computer or the like, dot pattern information of bit map fonts is developed in accordance with the text information and is printed by a printer mechanism.
A construction and operations of a conventional printing apparatus will be described hereinbelow with reference to a schematic block diagram shown in FIG. 5.
In the diagram, reference numeral 101 denotes an input controller for receiving and controlling text data 121 such as character codes or the like which are sent from the host computer; 102 a page memory to temporarily store the input text data; 103 a character pattern generator in which dot pattern information such as character codes and the like have been stored; 106 a main controller to control the whole apparatus; 107 an ROM in which a processing procedure (program) of the main controller 106 has been stored; 108 a work RAM which is used when executing the process; 109 a bit map memory to store the converted dot pattern information; 110 a parallel-to-series converter to convert the parallel dot pattern information into serial image data 122; and 111 a timing controller to control an output of the image data 122 in accordance with a sync signal 123 which is sent from a printer mechanism 112.
In the above construction, the main controller 106 controls the entire apparatus in accordance with the program stored in the ROM 107. The text data 121 such as character codes or the like which are sent from the host computer or the like is supplied from the input controller 101 and is temporarily stored into the page memory 102. The text data stored in the page memory 102 is sequentially read out from the head. By referring to the character pattern generator 103, the read-out text data is developed into the dot pattern information and stored into the bit map memory 109.
When the sync signal 123 is supplied from the printer mechanism 112, the timing controller 111 sequentially reads out the dot pattern information in the bit map memory 109 from the head. The read-out parallel dot pattern information is converted into the serial data by the P/S converter 110 and, after that, it is sent to the printer mechanism 112 as image data 122 and is printed.
However, in the above conventional apparatus, in the case where a bit map font of a resolution different from a resolution of the printer mechanism is used as a character pattern generator, there is a drawback such that if it is printed as it is, a size of character or the like changes (for instance, in the case where the resolution of the printer mechanism is equal to 600 dpi, if a bit map font of 300 dpi is used, a size of printed character is reduced into 1/2).